1. Field of the Invention
The present invention relates to a drive device for driving a disk storage medium such as CD-ROM, DVD-ROM, etc., and more specifically to a drive device for rotating various types of disk storage media having different diameters in a vertical plane, that is, a vertical drive device.
2. Description of the Related Art
A 12 cm diameter disk storage medium (herein after referred to as a 12 cm disk) and an 8 cm diameter disk storage medium (hereinafter referred to as an 8 cm disk) are suggested as disk storage media such as CD-ROM, DVD-ROM, etc. For a drive device for driving a disk, a drive device capable of driving disks having different diameters is suggested. As shown in FIG. 11, such a drive device includes a tray 3 which is able to get in and out of a drive device body 1 and supports a disk storage medium. The tray 3 is provided with a circular concave portion 4 for a 12 cm disk, and is also provided on the bottom of the concave portion 4 for a 12 cm disk with a circular concave portion 5 for an 8 cm disk. Furthermore, the drive device is provided with a head spindle motor passage groove 6 for the drive device body 1 from the centers of the concave portions 4 and 5. When a 12 cm disk is inserted into the drive device body 1, the spindle of the spindle motor provided in the drive device body 1 (not shown in the attached drawings) is fit into the center hole of the 12 cm disk by loading the 12 cm disk in the concave portion 4 for a 12 cm disk, thereby rotating the disk. Similarly, when an 8 cm disk is inserted, the drive device can rotate the 8 cm disk by loading it into the concave portion 5 for an 8 cm disk.
Recently, a vertical drive device for rotating a disk on a vertical plane has been provided with a view to reducing the installation space. With such a vertical drive device, a disk falls in the vertical direction if the disk is inserted into the concave portion 4 or 5 of the tray 3 having the above mentioned configuration as described above, or it slips off the concave portion 4 or 5 of the tray 3, thereby failing to support the disk storage medium in the concave portion 4 or 5. Therefore, the vertical drive device has disk support lugs 7 projecting inward at several points on the periphery of the concave portion 4 for a 12 cm disk as shown in FIG. 11. In this example, they are provided at four points, that is, two upper points and two lower points. The disk support lugs 7 prevent 12 cm disks from falling or being slipped off.
However, with the above mentioned configuration, since no disk support lugs are provided on the periphery of the concave portion 5 for an 8 cm disk, the vertical drive device has the difficulty in inserting an 8 cm disk into the tray 3 and supporting the disk because the above mentioned disk support lugs provided on the periphery of the concave portion 5 for an 8 cm disk are obstacles to a 12 cm disk to be inserted into the concave portion 4 for a 12 cm disk. A simple measure for solving the problem is an 8 cm disk mounted on the adapter formed similarly in outside diameter to fit the 12 cm disk when an 8 cm disk is used. Then, the adapter is inserted into the concave portion 4 for a 12 cm disk. However, with the configuration, a user has to additionally and wastefully purchase the adapter. Accordingly, such a measure is not economical.
On the other hand, Japanese Patent Laid-Open No. 2000-322803 discloses the technology in which the disk support lugs provided on the periphery of the concave portion for a 12 cm disk can move along the surface of the tray. By adjusting the rotating positions of the disk support lugs, the tip portions of the disk support lugs can be projected inward from the positions on the periphery of the common concave portion for a 12 cm disk to the positions on the periphery of the concave portion for an 8 cm disk. Therefore, the 8 cm disk can be inserted into the concave portion for an 8 cm disk and supported by the disk support lugs of the vertical drive device.
In the technology described by the above mentioned publication, the disk support lugs have to be moved along the surface of the tray, that is, along the vertical plane, and held at the positions after the movement, thereby complicating the structure of holding the movement positions. That is, in addition to the tray, the disk support lugs, the rotation arm for holding the lugs, the spindle for supporting the rotation arm, etc. are required as the components. Furthermore, the operation of setting the components is also required. Normally, the movement positions of the disk support lugs are held using the friction on the spindle supporting the disk support lugs. However, when the system is designed and produced such that a larger friction can be obtained, the operability for setting the movement positions of the disk support lugs is poor, and it is difficult to set the disk support lugs at desired positions. Then, undesired force is applied to the tray and disk support lugs during the operations, thereby possibly damaging the tray and the disk support lugs. On the other hand, if the system is designed and produced such that a smaller friction can be obtained, the disk support lugs are moved downward by the gravity through the frictional wear etc. by repetitive use. Then, the disk supporting function by the disk support lugs at the lower portion of the tray is reduced. Otherwise, the disk support lugs at the upper portion of the tray move up to the surface of a 12 cm disk. As a result, they become obstacles in loading and removing a 12 cm disk, thereby causing trouble.